Candidate List and Classification

The Candidate List is a roster of substances reported in U.S. workplaces that may deserve further scientific review as potential occupational carcinogens. It is created so the Secretary can identify substances that, based on a brief scientific review of available data, should receive more extensive scientific evaluation for possible regulation; see the Contents in 1990.121(a).

• The List is based on a short review of available data and is meant to start a deeper review process rather than serve as a final determination. See 1990.121(c).

Yes — data submitted by any person may be used as "available data" when preparing the Candidate List. The regulation explicitly includes "The data submitted by any person" as one source the Secretary will consider; see 1990.121(a)(1).

• This means researchers, employers, unions, or members of the public can provide information for OSHA's brief review, although submission does not guarantee listing or regulation.

Yes — OSHA may use data referred to by the Secretary of HHS or the Director of NIOSH, including their latest "Suspected Carcinogens" list or other communications. This is explicitly listed as a source of available data; see 1990.121(a)(2).

• Using these authoritative federal sources helps OSHA identify substances already of concern to health agencies.

OSHA may rely on literature referred to in U.S. Public Health Service Publication No. 149 as part of the "available data" used to identify candidate substances. The regulation lists this publication explicitly; see 1990.121(a)(3).

• If you use or produce chemicals discussed in that publication, OSHA could consider that literature when evaluating the chemical for the Candidate List.

Yes — OSHA includes data summarized and reviewed in the International Agency for Research on Cancer (IARC) Monographs among the available data it may use to prepare the Candidate List; see 1990.121(a)(4).

• IARC evaluations are widely used internationally to flag substances for further review and may contribute to OSHA's decision to list a substance as a candidate.

Yes — the Toxic Substances Control Act (TSCA) Inventory of Chemical Substances, published by EPA, is listed as a source of available data OSHA may use for the Candidate List; see 1990.121(a)(5).

• Inclusion of a substance in the TSCA Inventory can help OSHA identify chemicals present in commerce and workplaces for possible review.

OSHA may consider the Secretary of HHS's Annual Report to the President and Congress (required by the Community Mental Health Centers Extension Act of 1978, section 404(a)(9), 42 U.S.C. 285) as part of the "available data" for the Candidate List; see 1990.121(a)(6).

• This means relevant findings in that annual HHS report can feed into OSHA's initial identification of candidate carcinogens.

It means OSHA may use any additional relevant information the Secretary actually knows about, beyond the specifically listed sources, when deciding which substances to include on the Candidate List. The rule explicitly includes this catchall in 1990.121(a)(7).

• Practically, this allows OSHA to consider new studies, incident reports, or government findings that aren’t listed elsewhere, but only if the Secretary has actual knowledge of them.

A tentative designation means the Secretary has preliminarily marked a substance as a candidate for classification as either a Category I or Category II Potential Carcinogen to start a more extensive scientific review. The rule allows such tentative designations to initiate further review; see 1990.121(b).

• Tentative designation is not a final determination—it simply signals that OSHA intends to examine the substance more closely.

Yes — the Secretary may list substances on the Candidate List without assigning a tentative designation as Category I or II; the regulation allows listing with or without tentative designation to start further scientific review; see 1990.121(b).

• Listing without a tentative category simply indicates the substance merits further review but not yet a preliminary category assignment.

No — inclusion or exclusion from the Candidate List does not establish legal rights and is not subject to judicial review, nor is it the basis for legal action; see 1990.121(c).

• This means being listed does not by itself create enforceable obligations or private legal claims; listing initiates policy and scientific review rather than legal consequences.

No — inclusion and any tentative designation on the Candidate List do not reflect a final scientific determination that the substance is a Category I or II Potential Carcinogen; they indicate only that a thorough review should be conducted; see 1990.121(c).

• Employers should not treat listing as a final finding; instead, use it as a prompt to monitor the review and consider interim controls as appropriate.

Yes — the exclusion of a substance from the Candidate List does not prevent its later regulation as a potential occupational carcinogen; the rule states exclusion does not bar regulation; see 1990.121(c).

• OSHA may still pursue rulemaking or other actions based on other evidence or subsequent review.

The Secretary is responsible for preparing the Candidate List of substances that may need further scientific review; the duty is specified in 1990.121(a).

• In practice, this means OSHA (within the Department of Labor) acts under the Secretary’s authority to compile the list using the available data sources identified in the rule.

No — placing a substance on the Candidate List does not create an enforceable exposure limit or standard; it initiates further scientific review and possible future regulatory action, but is not itself a regulatory limit; see 1990.121(c).

• Employers should not assume a listed substance automatically requires compliance with new OSHA limits, though they should monitor developments and apply prudent controls where hazards are suspected.

A brief scientific review of the available data is used to identify substances for the Candidate List; that review serves to determine whether a more extensive scientific review is needed; see 1990.121(a).

• The brief review relies on the data sources listed in the regulation and is a screening step rather than a final determination.

Employers should treat a Candidate List entry as a warning sign to evaluate workplace exposure and consider appropriate interim controls, but they should not assume a final regulatory status has been reached. The regulation clarifies that listing is a policy decision to pursue more review rather than a final determination; see 1990.121(c).

• Practical steps: review Safety Data Sheets, assess exposure, implement feasible engineering or administrative controls, and follow updates from OSHA.

OSHA may rely on data summarized in the IARC Monographs of the World Health Organization as part of the available data used to compile the Candidate List; see 1990.121(a)(4).

• International reviews like IARC's are commonly used to flag chemicals for deeper national review because they consolidate global scientific evidence.

The Effective Date Note explains that paragraphs (a) and (b) were stayed to evaluate the impact of publishing the Candidate and Priority Lists and to reconsider the criteria used to establish them. That administrative history is noted under the section; see 1990.121.

• The stay reflects a procedural pause and review of how lists were developed and published; it does not change the rule language cited in the section.

The phrase means OSHA may consider substances that have been reported as present in any American workplace when preparing the Candidate List, so the scope includes any workplace in the U.S. where evidence shows the substance is used or exists; see 1990.121(a).

• In practice, this can include substances reported by industry, researchers, government agencies, or other reliable sources that indicate workplace presence.